claude-code-action/src/entrypoints/prepare.ts

#!/usr/bin/env bun

/**
 * Prepare the Claude action by checking trigger conditions, verifying human actor,
 * and creating the initial tracking comment
 */

import * as core from "@actions/core";
import { setupGitHubToken } from "../github/token";
import { checkHumanActor } from "../github/validation/actor";
import { checkWritePermissions } from "../github/validation/permissions";
import { createInitialComment } from "../github/operations/comments/create-initial";
import { setupBranch } from "../github/operations/branch";
import { configureGitAuth } from "../github/operations/git-config";
import { prepareMcpConfig } from "../mcp/install-mcp-server";
import { createOctokit } from "../github/api/client";
import { fetchGitHubData } from "../github/data/fetcher";
import { parseGitHubContext } from "../github/context";
import { getMode } from "../modes/registry";
import { createPrompt } from "../create-prompt";

async function run() {
  try {
    // Step 1: Setup GitHub token
    const githubToken = await setupGitHubToken();
    const octokit = createOctokit(githubToken);

    // Step 2: Parse GitHub context (once for all operations)
    const context = parseGitHubContext();

    // Step 3: Check write permissions
    const hasWritePermissions = await checkWritePermissions(
      octokit.rest,
      context,
    );
    if (!hasWritePermissions) {
      throw new Error(
        "Actor does not have write permissions to the repository",
      );
    }

    // Step 4: Get mode and check trigger conditions
    const mode = getMode(context.inputs.mode);
    const containsTrigger = mode.shouldTrigger(context);

    // Set output for action.yml to check
    core.setOutput("contains_trigger", containsTrigger.toString());

    if (!containsTrigger) {
      console.log("No trigger found, skipping remaining steps");
      return;
    }

    // Step 5: Check if actor is human
    await checkHumanActor(octokit.rest, context);

    // Step 6: Create initial tracking comment (mode-aware)
    // Some modes (e.g., future review/freeform modes) may not need tracking comments
    let commentId: number | undefined;
    let commentData:
      | Awaited<ReturnType<typeof createInitialComment>>
      | undefined;
    if (mode.shouldCreateTrackingComment()) {
      commentData = await createInitialComment(octokit.rest, context);
      commentId = commentData.id;
    }

    // Step 7: Fetch GitHub data (once for both branch setup and prompt creation)
    const githubData = await fetchGitHubData({
      octokits: octokit,
      repository: `${context.repository.owner}/${context.repository.repo}`,
      prNumber: context.entityNumber.toString(),
      isPR: context.isPR,
      triggerUsername: context.actor,
    });

    // Step 8: Setup branch
    const branchInfo = await setupBranch(octokit, githubData, context);

    // Step 9: Configure git authentication if not using commit signing
    if (!context.inputs.useCommitSigning) {
      try {
        await configureGitAuth(githubToken, context, commentData?.user || null);
      } catch (error) {
        console.error("Failed to configure git authentication:", error);
        throw error;
      }
    }

    // Step 10: Create prompt file
    const modeContext = mode.prepareContext(context, {
      commentId,
      baseBranch: branchInfo.baseBranch,
      claudeBranch: branchInfo.claudeBranch,
    });

    await createPrompt(mode, modeContext, githubData, context);

    // Step 11: Get MCP configuration
    const additionalMcpConfig = process.env.MCP_CONFIG || "";
    const mcpConfig = await prepareMcpConfig({
      githubToken,
      owner: context.repository.owner,
      repo: context.repository.repo,
      branch: branchInfo.claudeBranch || branchInfo.currentBranch,
      baseBranch: branchInfo.baseBranch,
      additionalMcpConfig,
      claudeCommentId: commentId?.toString() || "",
      allowedTools: context.inputs.allowedTools,
      context,
    });
    core.setOutput("mcp_config", mcpConfig);
  } catch (error) {
    const errorMessage = error instanceof Error ? error.message : String(error);
    core.setFailed(`Prepare step failed with error: ${errorMessage}`);
    // Also output the clean error message for the action to capture
    core.setOutput("prepare_error", errorMessage);
    process.exit(1);
  }
}

if (import.meta.main) {
  run();
}